enum E { a, b }

var a: any;
var b: void;

var x1: boolean;
x1 **= a;
x1 **= b;
x1 **= true;
x1 **= 0;
x1 **= ''
x1 **= E.a;
x1 **= {};
x1 **= null;
x1 **= undefined;

var x2: string;
x2 **= a;
x2 **= b;
x2 **= true;
x2 **= 0;
x2 **= ''
x2 **= E.a;
x2 **= {};
x2 **= null;
x2 **= undefined;

var x3: {};
x3 **= a;
x3 **= b;
x3 **= true;
x3 **= 0;
x3 **= ''
x3 **= E.a;
x3 **= {};
x3 **= null;
x3 **= undefined;

var x4: void;
x4 **= a;
x4 **= b;
x4 **= true;
x4 **= 0;
x4 **= ''
x4 **= E.a;
x4 **= {};
x4 **= null;
x4 **= undefined;

var x5: number;
x5 **= b;
x5 **= true;
x5 **= ''
x5 **= {};

var x6: E;
x6 **= b;
x6 **= true;
x6 **= ''
x6 **= {};